feat(sw): auto-reload page when service worker updates

Add updatefound listener in catalog.html that reloads the page
automatically when a new service worker is activated. This ensures
users get the latest HTML and JS without manual hard refresh.

pos/static/pwa/sw.js

@@ -1,20 +1,10 @@
 // /home/Autopartes/pos/static/pwa/sw.js
-// Nexus POS — Service Worker v5
+// Nexus POS — Service Worker v6
 // Self-contained vanilla JS. No external imports.
 
-const CACHE_NAME = 'nexus-pos-v5';
+const CACHE_NAME = 'nexus-pos-v6';
 
 const APP_SHELL = [
-  '/pos/login',
-  '/pos/sale',
-  '/pos/catalog',
-  '/pos/inventory',
-  '/pos/customers',
-  '/pos/invoicing',
-  '/pos/accounting',
-  '/pos/dashboard',
-  '/pos/config',
-  '/pos/reports',
   '/pos/static/css/tokens.css',
   '/pos/static/css/common.css',
   '/pos/static/js/app-init.js',
@@ -132,8 +122,8 @@ self.addEventListener('fetch', function (event) {
     return;
   }
 
-  // Don't cache login page
-  if (url.pathname === '/pos/login' || url.pathname === '/pos/login/') {
+  // HTML pages -> network-first (always fresh)
+  if (req.headers.get('accept') && req.headers.get('accept').indexOf('text/html') !== -1) {
     event.respondWith(networkFirst(req));
     return;
   }
@@ -181,7 +171,7 @@ self.addEventListener('fetch', function (event) {
     return;
   }
 
-  // Everything else -> cache-first
+  // Everything else (JS, CSS, images) -> cache-first
   event.respondWith(cacheFirst(req));
 });
 

pos/templates/catalog.html

@@ -293,7 +293,20 @@
   <script src="/pos/static/js/chat.js" defer></script>
   <script src="/pos/static/js/sync-engine.js" defer></script>
   <script src="/pos/static/js/onboarding.js" defer></script>
-  <script>if('serviceWorker' in navigator){navigator.serviceWorker.register('/pos/sw.js',{scope:'/pos/'});}</script>
+  <script>
+    if('serviceWorker' in navigator){
+      navigator.serviceWorker.register('/pos/sw.js',{scope:'/pos/'}).then(function(reg){
+        reg.addEventListener('updatefound', function(){
+          var newWorker = reg.installing;
+          newWorker.addEventListener('statechange', function(){
+            if(newWorker.state === 'activated'){
+              window.location.reload();
+            }
+          });
+        });
+      });
+    }
+  </script>
   <script src="/pos/static/js/pwa-install.js" defer></script>
   <script src="/pos/static/js/brand-catalog.js?v=3" defer></script>
 </body>